The present invention relates to a universally mountable video camera and more specifically relates to a security camera that can be used both in light and in dark conditions and has a compact structure suitable for mounting in a variety of positions and environments.
Video security cameras are a useful tool for enhancing safety in public and/or secure areas. A security camera allows activity to be monitored for identification, for alerting the occurrence of unwanted activity or intrusions and/or for providing a signal that may be recorded for later reference or potential use as evidence. For example, security cameras are commonly used to monitor activities in airports, banks, shopping areas, parking lots, train stations, etc.
Due to a heightened concern for safety aboard commercial passenger aircraft, security cameras are desired to monitor passenger activity in various places of an aircraft cabin, particularly in the vicinity outside the cockpit door. Additionally, the National Transportation and Safety Board recently proposed a regulation that would require the installation of a video camera in the cockpit of each commercial aircraft for recording pilot activities for use in analyzing aircraft accidents.
For use in commercial aircraft applications, each security camera is mounted at one of several typical installation locations in the aircraft cabin, each installation location having particular structural surroundings and desired orientation. Depending on a customer""s needs the aircraft can be equipped with one or more cameras at these various installation locations. The various installation locations may require a respective camera to be mounted behind a vertical wall, above a ceiling panel, to a bulkhead, etc., and each such location requires a particular camera view angle for monitoring a desired portion of the cabin. As a result, a variety of camera types have been designed in order to satisfy the particular constraints of the various camera installation locations. Duplicative resources are consumed in redesigning a camera for different installation locations, as each type of camera must be engineered, manufactured, supplied, purchased, stocked, installed and maintained. A need, therefore, exists for a security camera that can be universally mounted at each commonly desired installation location within an aircraft cabin.
Security cameras must operate in widely varying lighting conditions. Conventional security cameras are operable to generate a video image from visible light but are incapable of functioning in low-light conditions or darkness. A need therefore exists for a security camera that can be used in variable lighting conditions ranging from bright daylight to pitch dark.
The present invention provides an improved security camera that has enhanced utility. Preferably, the security camera has an external configuration that enables the camera to be mounted at any one of a plurality of locations in an aircraft cabin where a camera is desired. According to various aspects of the invention, the camera is adjustable to provide a desired view for a particular mounting position and/or to accommodate various lighting conditions. Such a universally mountable camera is particularly economical in a multi-camera aircraft cabin security system and/or for equipping multiple aircraft with security one or more cameras in a variety of installation locations, for example, outside a cockpit door or within a cockpit. The manufacturer, installer, and operator conserve resources by using a single type of universal security camera for each installation location, as opposed to using multiple types of cameras specifically configured for each installation location.
For example, in an embodiment, the camera includes a housing, a turret mounted to the housing for relative rotation about a turret axis, a lens assembly mounted to the turret wherein the lens assembly has a central optical axis that is at an oblique angle relative to the turret axis, and an optical sensor mounted to the lens assembly generally at a fixed focal plane, the sensor being rotatably adjustable relative to the optical axis.
According to a preferred embodiment of the invention, the lens assembly is configured to focus a range of light wavelengths on the fixed focal plane, wherein the range includes both visible and infrared light wavelengths. A suitable lens assembly has been found to include a plurality of lens elements rigidly mounted in position along the central optical axis within a barrel having a pinhole aperture at an object end of the lens elements. In a particular embodiment, four achromatic doublets are formed by at least some of the lens elements. The optical sensor is mounted to the barrel at the focal plane, opposite the object end. Such an embodiment advantageously permits the camera to be operated in conditions with or without visible light. In an embodiment, the camera additionally includes an infrared illumination source to provide infrared illumination when visible light is below a certain level. Advantageously, this feature enables the camera to be used in dark conditions where adequate illumination of the view area is not available from an external illumination source.
Depending on the selected orientation of the lens assembly to monitor a desired area, the optical sensor is rotatably adjustable relative to the lens assembly to square up the resulting video image for correct viewing orientation on a monitor. This adjustability provides a high degree of versatility to enable the camera to be mounted in various positions associated with the different installation locations and/or to change the viewing direction.
In an embodiment, the camera includes a transparent, protective window to cover the lens assembly. In such an embodiment, the barrel preferably has a beveled tip to enable the lens assembly to be positioned so that the pinhole aperture is close to an interior side of the window. The beveled barrel shaped facilitates a compact design.
In an embodiment, the camera additionally includes a filter to block visible wavelengths of light generated by the infrared illumination source from passing to an exterior of the camera. The filter advantageously avoids drawing attention to the camera from a human observer. In an embodiment, the filter may be selected to help camouflage the camera or to blend with its surroundings.
Another advantage of the present invention is that it provides a compact security camera that can be universally mounted in multiple installation locations within an aircraft cabin. This allows the use of a single design for all of the cameras of a multi-camera aircraft security system, conserving resources in designing, manufacturing, purchasing, stocking, installing and maintaining only one type of camera.
Additional features and advantages of the present invention are described in, and will be apparent from, the following description, figures and claims.